Don't forget, there was a minimum of one other survivor of the crash. It was one female flight attendent. It was reported that she walked to a special ops/rescue chopper. She bled to death of a femoral gash on the ride out. First off, a tourniquet should have been able to save her, or direct pressure on the gash in her leg. Even basic training teaches that in the Army.
Next, there were Spec Ops soldiers landed at the crash site. I've known some years back, and they ARE trained killers. Not like us regular soldiers were. They aren't known to question WHY a total elimination would be ordered. The right ones will just do it.
Also, the photos of the crashed plane show to many that some survivors probably were in the wreckage. Not many believe that any assassin was riding in the aircraft. It really would not have been intended nor needed to be anything more than a crash. But it didn't crash Hard Enough. :-)